1. Field of the Invention
The present invention relates to a rhythm creating system included in an electronic musical instrument to create a rhythm pattern.
2. Description of the Prior Art
Generally, in creating a desired rhythm on an electronic musical instrument, the desired rhythm is created by the user, a rhythm pattern is created by the user, the rhythm pattern is stored in a memory included in the electronic musical instrument and the electronic musical instrument reproduces the rhythm pattern. Alternatively a plurality of rhythms created by the manufacturer are stored in the memory included in the electronic musical instrument, a desired rhythm among those stored in the memory is selected by the user, and the electronic musical instrument reproduces the selected rhythm.
If a predetermined rhythm for one piece of music is desired to be played on the electronic musical instrument, the piece of music is divided into parts including a preliminary part, a theme part, an ending part and the like, and rhythm patterns for those parts are created and stored by the foregoing procedure. That is, according to a first system, which requires the user to create rhythms, rhythm patterns are created for the parts, respectively, by the user, the rhythm patterns for a plurality of bars conforming to the parts are assembled, the assembly of the rhythm patterns are stored in the memory of the electronic musical instrument, a rhythm pattern for the piece of music is constructed by storing the playing sequence of the rhythm patterns for the plurality of bars in the memory, and then the rhythm pattern for the piece of music is played. According to a second system, which enables the user to select a desired rhythm among those stored beforehand in the electronic musical instrument, a plurality of rhythm patterns are stored in the memory of the electronic musical instrument beforehand by the manufacturer, and the user selects a desired rhythm pattern among those stored in the memory, and the selected rhythm pattern is played on the electronic musical instrument.
If a new rhythm pattern is desired, the first system imposes troublesome work requiring much time on the user to create the new rhythm and to store the created rhythm in the memory every time a new rhythm is desired. Furthermore, the composition of a new rhythm pattern requires special knowledge of timing the play of different musical instruments in assembling the rhythm pattern. The second system requires search for a desired rhythm among many rhythm patterns stored beforehand in the memory by the manufacturer. If a greater number of rhythm patterns are stored beforehand in the memory, the probability of a desired rhythm pattern being included in the rhythm patterns stored beforehand may be higher. However, increase in the number of stored rhythm patterns will require more time for finding the desired rhythm pattern. If the number of stored rhythm patterns is reduced, it is possible that a desired rhythm pattern will not be included in the stored rhythm patterns.
A system proposed to solve such problems in Japanese Patent Laid-open (Kokai) No. Sho 61-188594 or Sho 61-18299 or Japanese Patent Publication (Kokoku) No. Hei 3-006515 stores a plurality of rhythm patterns for each musical instrument, selects a rhythm pattern for each musical instrument, and composes an integral rhythm pattern by integrating the selected rhythm patterns respectively for all the musical instruments. This system needs a memory having a storage capacity smaller than that of a memory needed by a system which stores integral rhythm patterns beforehand and has a certain degree of freedom of composing an optional rhythm pattern. However, this system also needs a memory having a large storage capacity to make possible a sufficiently high degree of freedom of composing a desired rhythm pattern. Thus, the number of rhythm patterns to be stored beforehand is limited by the storage capacity of a possible memory.